Question

我正在尝试使用LINQ加入两个表员工和部门，并尝试以下面的图像格式获得结果。有人可以帮助如何实现这一目标。

如何实现每个部门的员工。

这是我的代码

var EmpList = (from d in Department
 join e in Employee on d.ID equals e.ID
 select new
 {
   ID = d.ID, Name = d.Name, Location = d.location,  Employess =  
   e.FirstName, e.LastName, e.Gender
 });

以上代码未完全编写。我没有得到任何想法如何实现这一点。

var elist = from d in db.Departments
                    join e in db.Employees on d.ID equals e.ID
                    group d by e.DepartmentId into g
                    select new { Details = g };

Answer 1

假设你有这样的结构：

var depts = new[] {
    new Dept { ID = 1, Name = "IT", Location = "New York" },
    new Dept { ID = 2, Name = "HR", Location = "London" },
    new Dept { ID = 3, Name = "Payroll", Location = "Sydney" }
};

var employees = new[] {
    new Employee { ID = 1, FirstName = "Mark", DeptID = 1 },
    new Employee { ID = 2, FirstName = "Steve", DeptID = 3 },
    new Employee { ID = 3, FirstName = "Ben", DeptID = 1 },
    new Employee { ID = 4, FirstName = "Philip", DeptID = 2 },
    new Employee { ID = 5, FirstName = "Mary", DeptID = 2 },
    new Employee { ID = 6, FirstName = "Valarie", DeptID = 3 },
    new Employee { ID = 7, FirstName = "John", DeptID = 1 }
};

您可以使用LINQ Join和GroupBy来获取所需的数据：

var result = depts
    .Join(employees.GroupBy(x => x.DeptID), dept => dept.ID, empGroup => empGroup.Key,
        (dept, empGroup) => new { 
            Name = dept.Name, 
            Location = dept.Location, 
            Employees = empGroup.ToArray() 
        });

或者类似于SQL的语法：

var result = from dept in depts
             join empGroup in (
                from e in employees
                group e by e.DeptID into g
                select g
             ) on dept.ID equals empGroup.Key
             select new { 
                Name = dept.Name, 
                Location = dept.Location, 
                Employees = empGroup.ToArray()
             };

这实际上是做什么的？

员工按DeptID分组。
部门与此分组相结合，并生成所需格式的匿名对象集合。当然，您可以使用强类型类。

Answer 2

public class Meta
{
}

公共偏见类员工

{
    public string depart
    {
        get
        {
            EmpolyeeEntities db = new EmpolyeeEntities();

            var empid = db.Empolyees.Select(e=>e.Department).SingleOrDefault();

             var dpname = db.Department1.Where(x => x.Id == empid).Select(f => f.Department).SingleOrDefault();


            return dpname.ToString();
        }
    }

使用LINQ LAMBDA获得每个部门的员工

2 个答案: